A236517 Number of (n+1)X(2+1) 0..1 arrays with the difference of the upper median and minimum value of each 2X2 subblock in lexicographically nondecreasing order columnwise and nonincreasing rowwise

52, 264, 1256, 5670, 25023, 108214, 462970, 1962897, 8278491, 34768983, 145652451, 608974557, 2542990472, 10609555831, 44237987228, 184378860260, 768258530698, 3200511193171, 13331394907045, 55525565937033, 231251505598612

Offset

1,1

Comments

Column 2 of A236523

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 8*a(n-1) -8*a(n-2) -75*a(n-3) +168*a(n-4) +171*a(n-5) -664*a(n-6) +28*a(n-7) +1000*a(n-8) -411*a(n-9) -606*a(n-10) +337*a(n-11) +151*a(n-12) -94*a(n-13) -12*a(n-14) +8*a(n-15)

Example

Some solutions for n=4
..0..0..0....0..0..1....1..0..1....0..1..0....0..1..1....1..1..1....0..1..0
..1..0..0....0..0..1....1..1..0....0..1..1....1..0..1....1..0..1....1..1..1
..0..0..1....0..0..1....0..1..0....1..0..1....0..0..0....0..1..1....1..1..0
..1..0..0....1..0..1....1..1..1....1..1..1....0..0..0....1..0..0....1..1..1
..0..0..0....0..0..1....1..0..0....1..1..1....0..1..0....0..1..1....1..1..1

Crossrefs

Sequence in context: A122239 A086860 A070147 * A320556 A252335 A230533

Adjacent sequences: A236514 A236515 A236516 * A236518 A236519 A236520

Keyword

nonn

Author

R. H. Hardin, Jan 27 2014

Status

approved